外延温度对YBCO薄膜结构与性能的影响

摘要

采用化学溶液沉积法(CSD),在758℃到772℃不同温度下制备了一系列YBa2Cu3Ox(YBCO)薄膜.通过X射线衍射、扫描电镜观察和物性测量,研究了外延温度对其结构与性能的影响.研究结果表明,在760℃及770℃附近存在两个适合YBCO薄膜外延生长的温度区间,在这两个温区生长制备的YBCO薄膜具有良好的超导性能.760℃和770℃附近制备的样品的临界超导转变温度t分别为90K和89K,说明760℃附近的较低温区更适合YBCO薄膜的外延生长.760℃附近生长的薄膜在77K自场下的临界电流密度Jc可达到3MA/cm2.文中进一步对存在两个外延温区间的现象进行了讨论,其机制可能来源于自发形核与诱导外延生长之间的相互竞争.%YBa2Cu3Ox (YBCO) thin films sintered at different temperatures of 758℃ to 772℃ were prepared by chemical solution deposition,and the effect of sintered temperature on films'structure and properties was investigated by X-ray Diffraction (XRD),Scanning Electron Microscope (SEM) and Physical Property Measurement System (PPMS).According to the results,two temperature ranges suitable for film epitaxial growth around 760℃ and 770℃ were obtained in this paper.The physics properties of YBCO prepared in these two ranges show good performance,the critical transition temperature Tc can reach 90K and 89K by samples made in low and high sintered temperature range respectively,that means the low sintered temperature is better for films to epitaxial growth.And the critical current density Jc at 77K in self-field can be over 3MA/cm2 for films which made in low sintered temperature.The existence of two sintered temperature ranges may be caused by the competition of heterogeneous nucleation and induced epitaxial growth,this was also discussed in the paper.